The present invention relates to a stirrup prosthesis for implantation in a middle ear.
More particularly, it relates to a stirrup prosthesis which has an elastic clamping member placeable on a long anvil projection and formed as a clip with one open side.
Such a stirrup prosthesis is disclosed in the German patent document DE 296 09 687.3. The known prosthesis can be easily implanted by simple clamping on the long anvil projection. It is held exclusively by clamping action of the clamping member. Additional mounting means are therefore no longer needed. However, during the course of implantation the prosthesis can be tilted, and therefore the operation becomes difficult for the surgeons.
Accordingly, it is an object of the present invention to provide the stirrup prosthesis of the above mentioned general type, which is improved when compared with the existing prostheses and simplifies its implantation.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a stirrup prosthesis for implantation in a middle ear, comprising an elastic clamping member which is displaceable onto a long anvil projection and formed as a clip which is open at one side, said clip having at least one leg, said clip having an opening, and the at least one leg has a portion extending outwardly of said opening and formed as an arch with which the prosthesis is suspendable on the long anvil projection of a human middle ear before the displacement onto the anvil projection.
Since the prosthesis is suspended on the long anvil projection, the possibility is provided for an operator to exchange the operation instruments and for example to use a hook for placing the prosthesis on the long anvil projection.
The handling of the prosthesis can be also facilitated when it is provided on an outer side with a nipple for displacing the prosthesis onto the long anvil projection. The operator can engage the nipple with tweezers or a hook.
Instead of the nipple, the clip can be provided on its side which is opposite to the opening, with a notch for displacing the prosthesis on the long anvil projection. A corresponding instrument can be inserted into the notch.
Further advantages are provided when the clamping member does not completely surround the long anvil projection. Thereby the formation of a narrowing on the long anvil projection and occurrence of potential necrosis can be prevented.
It is especially advantageous when after the implantation the clamping member is arranged on the long anvil projection so that it does not abut in two regions of the periphery on the long anvil projection. Thereby, the supply vessels touch the long anvil projection only in the abutment regions. The remaining vessels extend in the both regions in which the clip does not abut against the anvil projection, so that the nutrient supply to the long anvil projection and proc. lenticularis is not endangered.
The prosthesis can be composed of a biologically compatible material. It is particularly advantageous when at least the clamping member is composed of titanium, since this material has an exceptional biocompatibility in a human middle ear.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.